The Mater Hospital in Dublin is urging the public to stay away from its Emergency Department (ED) due to high numbers and long waiting times.
In a statement, hospital management says people should attend their GP or the Rapid Injury Clinic in Smithfield for minor injuries, if possible.
The hospital is currently experiencing very high patient numbers and protracted waiting times in the ED.
Those attending will be managed according to priority.
Meanwhile, management at Cork University Hospital have requested that the public contact their GP prior to attending the Emergency Department if their needs are not urgent.
Figures from the HSE show that 1,735 patients presented to Cork University Hospital's ED between the 11th and 19th of this month.
The HSE says steps are being taken to address the issue which they say is a matter of priority.